Heat treatment of laser powder bed fused (LPBF-ed) Inconel 718 is crucial to achieve desired mechanical properties. Residual stresses, microsegregation, anisotropy, undesirable phases, layered structure, and poor surface quality are the challenges to be faced before LPBF-ed Inconel 718 parts can be industrially implemented. Although heat treatment of Inconel 718 after the LPBF process is widely discussed in the literature, an industrial approach has been neglected, or the proposed heat treatment processes do not address all the aforementioned challenges. Recently, extensive work has been done in the field of high-temperature heat treatment of this material, showing promise. Following current trends, a 4-stage high-temperature heat treatment, developed by considering the industrial approach, is proposed and evaluated in this paper. A structured, microstructural, and mechanical evaluation of the achieved material properties is presented. Several factors were taken into account, including testing orientation in relation to the build direction (0°, 45°, 90°), surface condition (abrasive blasted, machined), testing temperature (21 °C, 425 °C), specimen size (dia. 4.06 mm, dia. 6.35 mm), application of the HIP process (with, without). After eliminating the influence of surface, subsurface and internal defects, the material is characterized with isotropic properties, regardless of testing orientation in relation to the build direction. Isotropic properties are confirmed for both room temperature and elevated temperatures (425 °C). The obtained elongation is >1.5× higher than the literature reports for heat treated LPBF-ed Inconel 718, while maintaining high tensile strength at the average level found in the literature.

激光粉末床熔融 (LPBF-ed) Inconel 718 的热处理对于实现所需的机械性能至关重要。残余应力、微观偏析、各向异性、不良相、层状结构和较差的表面质量是 LPBF 处理的 Inconel 718 零件在工业上实施之前要面临的挑战。尽管文献中广泛讨论了 LPBF 工艺后 Inconel 718 的热处理，但工业方法已被忽略，或者提议的热处理工艺并未解决所有上述挑战。最近，在这种材料的高温热处理领域已经做了大量工作，显示出前景。根据当前的趋势，本文提出并评估了考虑工业方法开发的 4 阶段高温热处理。一个结构化的，介绍了对所获得材料性能的微观结构和机械评估。考虑了几个因素，包括与构建方向相关的测试方向（0°、45°、90°）、表面状况（喷砂、机加工）、测试温度（21°C、425°C）、试样尺寸（直径 4.06 毫米，直径 6.35 毫米），HIP 工艺的应用（有、无）。在消除表面、次表面和内部缺陷的影响后，材料具有各向同性的特性，而与构建方向的测试方向无关。在室温和高温 (425 °C) 下均确认了各向同性特性。获得的伸长率比热处理的 LPBF 镀铬镍铁合金 718 的文献报告高 1.5 倍以上，